Berger



Sept..24, 1963 K. BERGER 3,104,897

' ELECTRIC SWIVEL CONNECTOR Filed June 29, 1960 2 Sheets-Sheet 1 ,7 INVEN TOR. KOtF/YEL 5593a BY 544; an: I I

Sept. 24, 1963 K. BERGER ELECTRIC SWIVEL CONNECTOR 2 Sheets-Sheet 2Filed June 29, 1960 INVENTOR.

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ATTORNEYS 3,164,897 ELECTRIC SWIVEL CGNNECTOR Kernel Berger, KewGardens, NX. Berger Machine Products Inc, 74-16 Grand Ave, Maspeth, LongIsland, NY.)

Filed June 29, 1960, Ser. No. 39,599 1 Clair (Cl. 285-166) Thisinvention relates to an electrical swivel connector.

In general, said connectors are of two kinds, one being the so-calledball type which is occasionally referred to hereinafter as anunrestricted connector, and the other the so-called restrictedconnector. The fundamental difference between these is that in anunrestricted, i.e. ball, connector, one member can experience rotationalmovement with respect to another member about any one of threeintersecting rectangular axes, that is to say, true swiveling movement,whereas in the restricted connector, one member can experiencerotational movement with respect to the other about only a singletransverse axis, an additional mode of rotation being provided by asecond joint that permits rotation about an axis running longitudinallyof the connector. Because of the compound movement permitted by the twojoints, a restricted connector has come to be known as a swivelconnector, although this term is mechanically incorrect.

For various reasons, although ball connectors are less expensive,simpler and more compact, the trade prefers restricted, i.e. swivelconnectors. However, a certain basic difliculty arises in connectionwith the latter. The members which experience mutual relative movementabout the single axis have connecting bores for passage of a wire, sothat when the angle of rotation approaches 90, the end of the bore inone of the members will be exposed. Since this is unsightly andotherwise undesirable, heretofore various elaborate mechanicalarrangements have been devised to permit the requisite 90 mutualrotation to be experienced without exposing said bore. Despite thecomparatively complex and cumbersome structure that ensued, suchrestricted connectors have found favor in the public eye.

It is an object of my invention to provide an improved and simplifiedrestricted (swivel) connector which permits the desired 90 rotation totake place without the provision of any additional mechanical part forconcealing the aforesaid bore.

As note da-bove, in previous restricted (swivel) connectors, it has beencustomary to provide the needed second mode of rotation by a secondjoint at an end of the connector remote from the restricted joint. It isanother object of my invention to modify the aforesaid second jointwhereby to allow a restricted (swivel) connector to experience 90rotation without the utilization of an extra part at the restrictedjoint.

It is a further object of my invention to provide an electric swivelconnector of the character described, which is durable and inexpensive,and which lends itself to mass production.

Other objects of my invention in part will be obvious and in part willbe pointed out hereinafter.

My invention accordingly consists in the features of construction,combinations of elements and arrangements of parts, which will beexemplified in the electric fitting hereinafter described, and of whichthe scope of application will be indicated in the appended claims.

In the accompanying drawings in which is shown one of the variouspossible embodiments of my invention,

FIG. 1 is a side elevational view in partial section of an electricswivel connector constructed in accordance with my present invention andhaving the parts thereof arranged in alignment;

FIG. 2 is a side view of said connector, showing in full 3',ld4,897Patented Sept. 24, 1953 2 lines the parts rearranged to swing 90 to theleft, and in dot-and-dash lines the parts rearranged to swing 90 to theright;

FIG. 3 is a top view of said connector, showing in full lines the partsrearranged to swing 90 to the left, and in dot-and-dash lines the partssimilarly arranged but displaced approximately 30 in azimuth;

FIG. 4 is a front elevational view to a reduced scale of said swivelconnector; and

FIG. 5 is an exploded perspective view of the swivel connector.

Referring now in detail to the drawings, the reference numeral .ltidenotes my new electric swivel connector. Said connector includes anelongated casing 12 of tubular, i.e., hollow, open-ended, contour. Moreparticularly, the casing is formed adjacent its lower end to the shapeof a cylindrical portion 14, the axis of symmetry of which is coincidentwith the longitudinal axis of the casing. The lower edge of thecylindrical portion is inturned to provide a flange 16 that defines alarge constricted bottom opening 18 of somewhat smaller diameter thanthat of the cylindrical portion.

Above the cylindrical portion 14 the casing 12 flares outwardly at acomparatively small angle, e.g., in the neighborhood of 8, providingthereby a conoidal part 20. The top of the conoidal part runs smoothlyinto an upper mutilate-d cylindrical portion 22. Said portion 22includes two curved sections 24 (see FIG. 5) joined by parallel flats26. The curved sections are parts of a true cylinder and wouldconjointly define a single true cylinder except for the interruption,i.e., mutilation, of the parallel flats 26. For design appearance, theflats may be continued down the conoidal portion 20, tapering in widthas they approach the lower cylindrical portion 14.

The upper cylindrical portion 22 mounts at its top end an upperspherical segment 28. Said spherical segment is a smooth continuation of:both the curved sections 24 and the flats 26. The spherical segment 28terminates at a constricted top opening 34 of lesser diameter than theupper cylindrical portion 22, so that both the top and bottom ends ofthe casing '12 are constricted and thereby will captively retain thereinobjects of slightly larger diameter than said ends.

it will be appreciated that all of the sundry parts of the casingjointly comprise a single piece, the casing prefer-, ably constituting aone-piece tube of sheet metal which has been appropriately shaped bysuitable dies to assume the configuration described. It also should bementioned at this point that such con-figuration is not entirelyimparted until the last stage in the assembly of the electric swivelconnector. More particularly, the flange 16 is provided before assemblyand the spherical segment 28 is spun to its final form as the last stagein assembly, having theretofore constituted simply an extension of thecylindrical portions 22. This operation will be described in somewhatgreater detail hereinafter.

The electric swivel connector 10- further includes a ball 32 which may,if desired, constitute, as illustrated, a die-casting, although it iswithin the scope of my invention to manufacture the same by turning orfrom sheet metal by a series of forming operations. Said ball includes ahollow spherical portion 34 from one sideof which extends, preferably inone piece therewith, a threaded tubular shank 36, a flange 38 beingprovided at the base of the shank where it joins the spherical portion.The flange is formed with a pair of diametrically opposed parallel flatsit? to assist in coupling the shank to a threaded female part. Thebottom of the spherical portion is formed with a large opening 42 forpassage of a wire extending through the connector. The spherical portion34 includes a pair of diametrically opposed flats 44 at the ends of 3,major diameter of the ball perpendicular to the longitudinal axis of theshank 36. Said ball has a diameter substantially equal to the diameterof the internal surface of the upper spherical segment 2%.

The islooated within the casing '12 at the upper end thereof, and isseated in the spherical segment 28 with the threaded shank 36, theflange 38, and the adjacent part of the spherical portion 34 protrudingfrom the top opening 34) of the casing, and with the flats 44 rotatablyresting against the inner surfaces of the flats 26. It will be observedthat at diametrically opposite edges of the upper opening 3%, the upperspherical segment 28 is deeply notched as at 46. The location of thesenotches with respect to the center of the spherical portion 34 is suchthat the neck 48 between the flange 38 and the spherical portion willabut said notches to confine the extremes of movements of the shank 36with respect to the casing to an angular range less than 180. Moreparticularly, this range is sufiiciently below 180", e.g. about 90, toprevent the opening 42 from being exposed as the ball turns. It furtherwill be observed that the cooperation between the flats 26 and 44restricts rotation of the ball with respect to the casing to turningmovement about a single axis that is perpendicular to the longitudinalaxis of the shank 36, is perpendicular to the flats 26, 44, iscoincident with a major axis of the spherical portion 34, and issubstantially centered in the flats 44, As soon will be seen, the ball32 is biased against the upper end of the casing, so that it can turn,subject to stop limits, in the manner aforesaid.

The portion of the ball 32 located within the casing 12 rests on anopen-ended thimble 50. Said thimble is in the form of a sheet metal cup,the major portion of which constitutes a cylindrical side wall 52 havingan out-turned annular spherically segmental flange 54 at its upper end.Preferably the flange is shaped to match the curvature of the sphericalportion 34', so that there is a nice fit between these parts. Adjacentits base the thimble is provided with an in-turned shoulder 56 runninginto a short tubular projection 58 co-am'al with the side wall 52,

The biasing action above described is furnished by an open-ended helicalcompression spring 60, the upper end of which telescopically receivesthe short tubular projection 58. It is apparent from the dnawings thatthe thimble 50 is located within the casing 12, and that the spring 60which biases the thimble against the ball, and the ball in turn againstthe constricted upper end of the casing, likewise is located internallyof the casing.

I further provide an open-ended ferrule 62 constituting a tubular sleeve64 having a frusto-conical outwardly extending flange 66 at its lowerend. The sleeve 64 is of proper diameter to telescopically fit withinthe lower end of the spring '60. The flange 66 terminates in a largediameter short tube 68. The lower end of the spring 60 telescopicallyreceives the tubular sleeve 64 and bears against the flange 66.

Pursuant to my invention, I provide an unrestricted type joint 70 at thelower end of the casing, that is to say, a joint which permits rotationabout three intersecting rectangular axes, in other words, a true swiveljoint. This joint does have a diflerent kind of restriction, which Iwill refer to hereinatter as a limitation, in that Iotation about two ofthese axes is limited to approximately 45 to either side of center,i.e., about 90 through center, and about the third axis to less than 360'I obtain the desired action by utilizing a second ball '72 which,desirably, is manufactured in the same manner as the first ball 32, thatis to say, preferably by diecasting, although optionally by any othermode or fabrication. The ball 72 includes a hollow spherical portion 74from which there extends a threaded tubular shank 76 provided with theusual shoulder 73, the latter being connected to the spherical portionat a neck 80. The top of the spherical portion is formed with a largeopening 82 for passage of a Wire extending through the joint. For apurpose which soon will be apparent, I mutilate the surface of thespherical portion 74 along a great circle zone running in a generaldirect-ion from the opening 82 7 toward the shank 76. This mutilationmay take the form of a raised ridge, a fiat or a groove, and hereinconstitutes a groove 84 lying on a great circle of the spherical portion74. The upper end of the groove stops short of the opening 82. The lowerend of the groove stops short of the neck 80.

The trusto conical flange 66 seats the spherical portion 74 of the ball72 and said flange bears against said spherical portion under the forceexerted by the spring 6t), that is to say, said spring urges the twoballs 32, 72 I to swivel about a point on this axis at the center of thespherical portion 74. The ferrule 62 includes an internally protrudinglug 36 the surface whereof is shaped to ride smoothly in the groove 84.-The lug is located on the tube 68 at any point in a plane perpendicularto the longitudinal axis of the casing and intersecting the sphericalportion 74 along a great circle so that it is disposed at an end of amajor diameter of the spherical portion 74 of'the lower ball. Theferrule 62 additionally is provided with an erect rotating stop arm 38which rides along, i.e., adjacent, the inner surface of the cylindricalportion 14 of the casing part. Said portion has .an inwardly protuberantboss 90 in the path swept by the arm 88.

Before assembly of the parts, the casing 12 has an unconstricted topend, that is to say, the upper spherical segment 28 has not yet beenformed but the flange-16 already has been provided. At this time theupper end of the casing constitutes an unmodified continuation of theupper cylindrical portion 22, including the curved sections 24 and theflats 26. The various parts are inserted into the casing in the ordershown in FIG. 1, that is to say, the ball 72 is seated in the opening 18with the shank 76, flange 78, neck and adjacent part of the sphericalportion 74 protruding from the open lower end of the casing.

Next, the ferrule 62 is placed atop the ball with the lug 86 riding inthe groove 84 and the spring 60 is seated on the sleeve 64 of theferrule. The tube 68 is located between the ball 72 and the cylindricalportion of the casing so that the ball is rotatably encaged between theferrule 62 and the lower end of the casing. Next the thimble 50 is seton the spring 60, with the tubular projection 58 inside the spring.Finally, the ball 32 is seated on the thimble 54 At this time, due tothe lengths of the sundry parts in a direction parallel to thelongitudinal axis of the casing, the ball 32 will be too high in thecasing. Accordingly, the spring 60 is compressed by forcing the ball 32downwardly until it is located at its proper position within the casing.Then, with suitable spinning machinery, the spherical segment 28 isformed, thereby constricting the upper end of the casing and captivelylocking all of the parts therein. Spinning the upper segment 28 provides7 a spherical seat for the upper ball 32. The flange 16 furnishes aswivel seat for the lower ball 72.

When the two balls 32, 72 are angularly arranged so that theirrespective shanks 36, 76 are co-axial, as shown in FIG. 1, an electricwire can he threaded in a straight line through the connector 10. Thus,referring to FIG.

1, it will be seen, reading from top to bottom, that aligned straightopenings are formed in the ball 32, the thimble 50, the spring 60, theferrule 62, and the ball 72.

The upper ball 32 is capable of restricted movement, that is to say,movement about a single axis, perpendicular to the longitudinal axis ofthe casing between an inline position (the position shown in FIG. 1) andtwo extreme angular positions (shown in FIG. 2), in one of which the.neck 48 will abut one of the notches 46, in the other of which the neckwill abut the opposite notch. As mentioned earlier, the notches are soarranged that in neither of these extreme positions will the opening 42be exposed. However, because of this limitation of movement about asingle perpendicular axis, the upper ball 32 is not capable of swingingup to 90 to both sides with respect to the longitudinal axis of thecasing, the actual extremes of movements being about 45 as indicated inFIG. 2. It is in order to compensate for this limitation that I haveprovided in connection with the restricted joint at the upper end of thecasing, an unrestricted second joint, albeit of limited movement, at thelower end of the casing.

At the lower end of the casing, the ball 72 can experience several modesof movement, all of which are limited, that is to say, the ball hasunrestricted (true swivelling) limited movement. Thus, said ball is ableto turn about one horizontal axis (assuming the connector to have itslongitudinal axis vertically oriented), this being the axisperpendicular to the plane of the diametrical groove 84. When thisturning movement is experienced, the lug 86 rides in the groove 84.Additionally, the ball can turn about a second horizontal axis at rightangles to and intersecting the foregoing *axis, that is to say, about ahorizontal axis running from the lug 86 to the longitudinal axis of thecasing. Such movement is permissible because the lug 86 is loocated tolie approximately at the end of a major diameter of the ball 72.Furthermore, the ball can turn about an axis coincident with thelongitudinal axis of the casing. This latter movement is accompanied bymovement of the ferrule 62 to which the ball is keyed by the lug andgroove. Such latter turning about the axis of the casing causes the stoparm 88 to swing about the inside of the casing.

It now will be apparent that movement of the lower ball 72 with respectto the casing can take place about three intersecting axes and thereforeis of the so-ca-lled unrestricted type. Although the angular movement isunrestricted, it is limited in extent to prevent cutting of the wirewhich extends through the lower joint, twisting of said wire, orexposure of the opening 82. Movement of the ball 72 with respect toeither of the two horizontal axes above described is limited by abutmentof the neck 80 against the edge of the opening 18. Additionally,rotation of the ball about the horizontal axis perpendicular to theplane of the groove 84 is limited by abutment of the lug 86 against theshoulders at the ends of the groove. Rotation of the ball about thelongitudi nal axis of the casing is limited by abutment of the stop arm88 against the boss 90.

The parts are so dimensioned that the upper ball 32 can swing about 45to either side of the longitudinal axis of the casing, and so that thelower ball 72 likewise can turn about 45 to either side of thelongitudinal axis of the casing. These two angles are complemental,i.e., add up to 90, so that if both balls are turned in the samedirection to their extreme limits, the longitudinal axis of the shank 36will be perpendicular to the longitudinal axis of the shank 76, asillustrated in full lines in FIG. 2. If it is desired to swing the uppershank 36 to its diametrically opposed position, as shown in dot-and-dashlines in FIG. 2, the two balls are swung to their opposite extremelimits, or the casing is turned about the vertical axis of the lowerball 72, this latter motion being illustrated in FIG. 3. It will beappreciated by those skilled in the art that the limitation upon thelastmentioned movement, by abutment of the stop arm and boss, willprevent the wire that passes through the connection from being twistedto the point of breaking.

It thus will be seen that I have provided an electric swivel connectorwhich achieves the various objects of my invention, and is well adaptedto meet the conditions of practical use.

As various possible embodiments might be made of the above invention,and as various changes might be made in the embodiment above set forth,it is to be understood that all matter herein described orshown in theaccompanying drawings is to be interpreted as illustrative and not in alimiting sense.

Having thus described my invention, I claim as new and desire to secureby Letters Patent:

An electric swivel connector comprising an open-ended hollow elongatedcasing having seats at opposite ends thereof, said casing having a pairof diametrically opposed flats near one of the seats and a cylindricalportion near the other seat, the cylindrical portion having an axiscoincident with the longitudinal axis of the casing, a first hollowopen-ended ball having diametrically opposed flats engaging the flats inthe casing, said ball being seated in the seat near the flats in thecasing whereby said first ball is mounted in said casing for rotationrelative thereto only about a single axis transverse to the length ofthe casing, said ball having a shank extending therefrom and protrudingfrom said casing to limit such rotation of: the ball about said singleaxis to an are less than 180, a second hollow open-ended ball, a tubularmember rotatable in the cylindrical portion of the casing, the secondball being seated against the second seat of the casing, cooperatingmeans in the second ball and tubular member for limiting rotation of thesecond ball relative to the tubular member to an axis transverse to thelength of the casing, whereby said second ball is mounted in the casingfor rotation about three rectangular axes one of which is parallel tothe length of the casing, said second ball having -a shank extendingtherefrom and protruding from said casing to limit such rotation of thesecond ball about two of said rectangular axes other than the parallelaxis to an are less than 180, means to limit rotation of the tubularmember with respect to the casing to an arc exceeding 180 and less than360 whereby rotation of the second ball relative to the casing about theparallel axis is similarly limited, and hollow open-ended spring meansforcing said balls apart. 3

References Cited in the file of this patent UNITED STATES PATENTS1,665,810 Gillick Apr. 10, 1928 1,927,703 Glowacki Sept. 19, 19332,862,730 Berger Dec. 2, 1958 2,887,329 Blakely May 19, 1959 3,012,798Berger Dec. 12, 1961

